North Korea beat Japan 1-0 in a 2014 World Cup qualifier on Tuesday, with Pak Nam-chol heading the winner in the 50th minute.
The final final whistle sparked wild celebrations at Pyongyang's Kim Il-sung stadium despite the fact North Korea had already been eliminated and Japan were already assured of progression to the final qualifying round.
"We didn't do anything right for 90 minutes," Japan defender Yasuyuki Konno said. "They dominated us. We were pathetic."
Asian champions Japan, who have 10 points from five matches, lost for the first time in 17 games under Italian coach Alberto Zaccheroni.
"They were very physical and made it very difficult," the Italian said. "North Korea had failed to qualify for the last round so this will be some consolation for them."
Uzbekistan will join Japan in the final round of qualifiers from Group C.